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Pola Musiman dan Antar Tahunan Salinitas Permukaan Laut Di Perairan Utara Jawa-Madura Najid, Ahmad; Pariwono, John I; Bengen, Dietriech G; Nurhakim, Subhat; Atmadipoera, Agus S
Maspari Journal : Marine Science Research Vol 4, No 2 (2012): Edisi Juli
Publisher : UNIVERSITAS SRIWIJAYA

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (513.856 KB) | DOI: 10.36706/maspari.v4i2.1383

Abstract

ABSTRACTWatermass of Java Sea is already known having a strongly connection with monsoon system in Indonesian region. Study of temperature valiability for and/or its relation to exploitation of marine and coastal resources have been done by scientists before hand. But the salinity condition is rare to studied, while the characteristic is important to the real life application. The sea surface salinity data archive, is primarily used in this study, is a monthly average within January 1994 – December 2010 by a spatial resolution of 1o x1o. Dataset of wind from ECMWF as a secondary parameter, have been monthly averages both for east-west (zonal) component and north-south (meridional) component, it is derived from 10 meters above sea level within period of January 1994 – December 2010, by a spatial resolution of 2.5o x 2.5o. Descriptive analysis have been done in order to get a complete picture of the SSS seasonal fluctuation. The results shows that SSS in Java Sea having a seasonal variability, which indicated by appearences of two SSS maximum and two SSS minimum annualy. Based on monthly average in the northern part of Java-Madura Seas, the SSS is haveing range of 32,0 PSU – 34,4 PSU. In the first transitional monsoon (Maret-April-Mei), SSS is relatively lower than others, i.e. NW monsoon, SE monsoon, and the second transitional monsoon, where it is found a core low SSS consentrated in the western part of Java Sea and also in south of Makassar strait.Keywords: Sea surface salinity, seasonal fluctuation, wind monsoon system, Java sea ABSTRAKMassa air Laut Jawa telah diketahui memiliki hubungan yang erat dengan sistem muson di Indonesia. Kajian variabilitas temperatur terhadap dan/atau keterkaitannya dengan pemanfaatan sumberdaya laut dan pesisir juga telah banyak dilakukan. Sedangkan untuk kondisi salinitas belum banyak dikaji, padahal secara aplikasi adalah penting untuk diketahui karakteristiknya. Data arsip Salinitas Permukaan Laut (SSS), digunakan sebagai data primer dalam penelitian ini, merupakan rerata bulanan dari Januari 1994 – Desember 2010 dengan resolusi spasial 1o x1o. Data angin yang bersumber dari ECMWF sebagai data sekunder merupakan rerata bulanan  untuk komponen timur-barat (zonal) dan komponen utara selatan (meridional) pada ketinggian 10 meter di atas permukaan laut dari Januari 1994 – Desember 2010, dengan resolusi spasial 2,5o x 2,5o. Analisa deskriptif dilakukan untuk menghasilkan pemahaman yang komplit. Hasil kajian menunjukkan bahwa SSS di perairan Laut Jawa memilik variabilitas antar musim yang diindikasikan dengan dua puncak SSS maksimum dan dua lembah SSS minimum dalam setahun. Berdasarkan rerata bulanan pada tahun 1994 – 2010 di Laut Utara Jawa-Madura, SSS berkisar antara 32,0 PSU – 34,4 PSU. Musim peralihan I (Maret-April-Mei) SSS relatif terendah dibandingkan pada musim yang lain, yakni musim barat, musim timur, dan musim peralihan II, dimana SSS rendah terkonsentrasi di bagian timur laut Jawa, di selatan Selat Makasar.Kata kunci: salinitas permukaan laut, fluktuasi musiman, sistem angin muson, Laut Jawa
HUBUNGAN SUHU PERMUKAAN LAUT DAN KLOROFIL-A TERHADAP HASIL TANGKAPAN IKAN CAKALANG (Katsuwonus pelamis, Linne) DI PERAIRAN BAGIAN TIMUR SULAWESI TENGGARA Muhammad Syahdan; M. Fedi A. Sondita; Agus Atmadipoera; Domu Simbolon
Buletin PSP Vol. 16 No. 2 (2007): Buletin PSP
Publisher : Institut Pertanian Bogor

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

Sea surface temperature (SST) and chlorophyll-a (chl-a) are the important oceanographic parameters determining the abundance and distribution of marine pelagic organism, include skipjack tuna. The aim of this research is to determine the relationship between SST and chl-a concentration with production of skipjack tuna off eastern coast of Southeast Sulawesi. Such relationship can be used to identify potential fishing ground of skipjack tuna.SST was derived by NOAA-AVHRR 16 and the data was collected from Lembaga Antariksa dan Penerbangan Nasional (LAPAN). Chl-a was derived from TERRA-MODIS satellite and the data were obtained from Colorado Center of Astrodynamics Research (CCAR) website. Skipjack tuna production data were obtained from direct observation and pole and line fishermen reports (log book) from March to June 2004.The lowest SST occured at March, while the highest at April and May 2004. The higher SST indicated a flow of water mass from nothern area to southern area. From March to May 2004, there was no significant change in chl-a concentration. In that period, the chl-a concentration was relative low and uniformly distributed but significant spatial variation was observed in June. The optimum observed SST for skipjack fishing in the studied area ranged from 25 to 26 °C and from 31,5 to 32,5 °C ; the optimum chl-a concentration ranged from 0,38 to 0,52 mg/m3. SST did not show strong influence on the catch of skipjack tuna ; the catch of skipjack tuna more influenced by chl-a concentration. The most productive fishing ground ; i.e. the potential fishing area off estern coast of Southeast Sulawesi are between Wawonii Island and Menui Island and eastern Umbele Island/northwestern Menui Island.
ANALISIS KUALITAS AIR DAN TEKSTUR SEDIMEN PADA DAERAH TERSEDIMENTASI DI LAGUNA SEGARA ANAKAN CILACAP Lilik Kartika Sari; Luky Adrianto; Kadarwan Soewardi; Agus S Atmadipoera; Endang Hilmi
Journal Omni-Akuatika Vol 11, No 2 (2015): Omni-Akuatika November
Publisher : Fisheries and Marine Science Faculty - Jenderal Soedirman University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20884/1.oa.2015.11.2.962

Abstract

This paper provides an overview of the environmental quality of areas affected by sedimentation on a lagoon. Observations made on water conditions as well as the texture of sedimennya. The observed water quality parameters is salinity, pH, NO3-N, PO4-P, COD and BOD. The observation is performed also on sediment texture on the 6 stations that represents the condition of the lagoon. The addition of LANDSAT Imagery based on land area in the province of Laguna Segara Saplings in two decades is of 823,9 ha per year.Keywords : sedimentation, the quality of the environment
Stratification and Characteristic of Water Masses in Selayar Slope-Southern Makassar Strait Isnaini Prihatiningsih; Indra Jaya; Agus Saleh Atmadipoera; Rina Zuraida
Journal Omni-Akuatika Vol 17, No 1 (2021): Omni-Akuatika May
Publisher : Fisheries and Marine Science Faculty - Jenderal Soedirman University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20884/1.oa.2021.17.1.620

Abstract

Selayar slope is the confluence of the Indonesian Throughflow (ITF) from the Makassar Strait and seasonal Java-Flores current. The CTD data from Java-Makassar-Flores (JMF) Cruise where an intensive 24-h CTD “yoyo” measurement was conducted in Selayar Slope is used to determine the stratification and characteristic of water masses in the Selayar slope - southern Makassar Strait.  The analyses were performed using TS Diagram processed with Matlab and Ocean Data View (ODV). The surface potential density of 24.25 sq  with stratification of water masses is dominated by Makassar ITF. The water mass with higher salinity (34.6 psu) is North Pacific Subtropical water (NPSW) and lower salinity (34.44 psu) is North Pacific Intermediate Water (NPIW). However, water mass with density above 24.25 sq  caused NPSW to be drastically extracted by less-saline water (34.15 psu) originated from Java Sea, where salinity profiles are more clearly observed between surface density of 22.0 sq and 23.50 sq.. Keyword: stratification and characteristic, water mass, Selayar Slope, JMF Cruise, TS Diagram
INTRA-SEASONAL VARIABILITY OF NEAR-BOTTOM CURRENT IN THE HALMAHERA SEA Marlin C Wattimena; Agus S Atmadipoera; Mulia Purba; Ariane Koch-Larrouy
Jurnal Ilmu dan Teknologi Kelautan Tropis Vol. 6 No. 2 (2014): Electronik Jurnal Ilmu dan Teknologi Kelautan Tropis
Publisher : Department of Marine Science and Technology, Faculty of Fisheries and Marine Science, IPB University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1409.838 KB) | DOI: 10.29244/jitkt.v6i2.9003

Abstract

The secondary entry portal of the Indonesian Throughflow (ITF) from the Pacific to Indian Oceans is considered to be via the Halmahera Sea (HS). However, few ITF studies have been done within the passage. This motivated the Internal Tides and Mixing in the Indonesian Througflow (INDOMIX) program to conduct direct measurements of currents and its variability across the eastern path of the ITF. This study focused on the intra-seasonal variability of near-bottom current in HS (129°E, 0°S), its origin and correlation with surface zonal winds and sea surface height over the equatorial Pacific Ocean. The result showed a strong northwestward mean flow with velocity exceeding 40 cm/s, which represented the current-following topography with the northwest orientation. Meridional current component was much stronger than the zonal component. The energy of power spectral density (PSD) of the current peaked on 14-days and 27-days periods. The first period was presumably related to the tidal oscillation, but the latter may be associated with surface winds perturbation. Furthermore, cross-PSD revealed a significant coherency between the observed currents and the surface zonal winds in the central equatorial Pacific zonal winds (180°E-160°W), which corroborates westward propagation of intra-seasonal sea surface height signals along the 5°S with its mean phase speeds of 50 cm/s, depicting the low-latitude westward Rossby waves on intra-seasonal band. Keywords: current, equatorial Pacific Ocean,  zonal winds, sea surface height, Halmahera Sea
A NUMERICAL MODELING STUDY ON UPWELLING MECHANISM IN SOUTHERN MAKASSAR STRAIT Agus S Atmadipoera; Priska Widyastuti
Jurnal Ilmu dan Teknologi Kelautan Tropis Vol. 6 No. 2 (2014): Electronik Jurnal Ilmu dan Teknologi Kelautan Tropis
Publisher : Department of Marine Science and Technology, Faculty of Fisheries and Marine Science, IPB University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (2667.723 KB) | DOI: 10.29244/jitkt.v6i2.9012

Abstract

ABSTRACT While it has been well documented in the previous studies that upwelling events in the southern Makassar Strait (MAK) during the Southeast Monsoon (SEM) period are associated with low sea surface temperature (SST) and high chlorophyll-a (Chl-a) concentrations in the seawater, the dynamic and physical processes that trigger these upwelling events are still less well understood. In the present study we proposed a mechanism of the upwelling event using a numerical model of the Regional Ocean Modeling System (ROMS).  Model validations showed a high correlation of SST climatology between the model and the NOAA-AVHRR satellite data. Moreover, velocity fields of the Indonesian Throughflow (ITF) Makassar in Libani Channel was well reproduced by proposed model, revealing an intensification of the flow centered near 120 m depth, which is in good agreement with the observation data. The model demonstrated that during the SEM period strong southeasterly winds that blow over southern Sulawesi Island can increase high vertical diffusivity and heat loss through heat flux. Hence, these physical processes lead to increased vertical mixing that, in turn, generates low SST, as a proxy of upwelling event. Furthermore, the upwelling process is enhanced by the ITF Makassar jet that creates large circular eddies flow due to complex topographic within the triangle area of southern Makassar - eastern Java Sea - western Flores Sea. The eddies generate the area of convergence offshore along the ITF pathways and divergence area in the coastal waters close to southern Sulawesi Island.  Model experiment with closing/opening Selayar Strait revealed a change of intensity and area of upwelling, suggesting that the Selayar Island forms a barrier for the outflow from MAK to northern part of Flores Sea. Keywords: Upwelling, ITF Makassar, SE monsoon winds, ROMS-AGRIF, Makassar Strait.
TURBULENT MIXING IN OMBAI STRAIT Yulianto Suteja; Mulia Purba; Agus S. Atmadipoera
Jurnal Ilmu dan Teknologi Kelautan Tropis Vol. 7 No. 1 (2015): Elektronik Jurnal Ilmu dan Teknologi Kelautan Tropis
Publisher : Department of Marine Science and Technology, Faculty of Fisheries and Marine Science, IPB University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (704.301 KB) | DOI: 10.29244/jitkt.v7i1.9778

Abstract

Ombai Strait is one of the exit passages of Indonesian Throughflow (ITF) which conveys hotspot of strong internal tidal energy. Internal tide is the one of main energy which causes mixing processes in the oceans and could lead to changes in water mass characteristics. The purpose of this research was to estimate the turbulent mixing by using Thorpe analysis. Nine CTD cast were obtained for one tidal cycle (24 hours) in Ombai Strait. The results showed the average value of the turbulent mixing is 833.5 x 10-4 m2s-1, the highest found in deep homogeneous layer (2383.4x 10-4 m2s-1), followed by mixed surface layer (103.0 x 10-4 m2s-1) and thermocline (14.2 x 10-4 m2s-1). This Turbulent mixing value is much higher than the previous measurement in Indonesian Sea. This is presumably due to the strong internal tidal energy and its interaction with existing deep sill in Ombai Strait. Keywords: Indonesian throughflow (ITF), Ombai Strait, turbulent mixing
OBSERVATION OF COASTAL FRONT AND CIRCULATION IN THE NORTHEASTERN JAVA SEA, INDONESIA Agus S. Atmadipoera; Edi Kusmanto; Adi Purwandana; I Wayan Nurjaya
Jurnal Ilmu dan Teknologi Kelautan Tropis Vol. 7 No. 1 (2015): Elektronik Jurnal Ilmu dan Teknologi Kelautan Tropis
Publisher : Department of Marine Science and Technology, Faculty of Fisheries and Marine Science, IPB University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (2139.873 KB) | DOI: 10.29244/jitkt.v7i1.9786

Abstract

The structure and spatial extent of a coastal front and circulation in the shallow (<55 m depth) northeastern Java Sea in Indonesia was investigated with a new dataset of high-resolution conductivity-temperature-depth (CTD) and along-track shipboard acoustic Doppler current profiler (SADCP) during a DIKTI-LIPI 2010 joint research cruise on R.V. Baruna Jaya 8.  The coastal front separates fresh warm coastal water derived mainly from Barito River discharge and the saline, cool Java Sea water.  The surface fresh water plume extends approximately 760 km from the Barito River estuary to the south, and its thickness varies from the surface to 10 m and 20 m depth, depending on its proximity to the fresh water source.  The front is aligned a northeast and east direction, probably related to a meandering of strong northeastward monsoon current in the eastern part of the Java Sea during the observation time. Keywords: hydrographic measurement, coastal front, Matasiri Islands, Barito River, the northwest monsoon current
RESPONSE OF SEA SURFACE TEMPERATURE (SST) AND CHLOROPHYLL-A ON MADDEN JULIAN OSCILLATION (MJO) IN INDONESIAN SEAS Nabil Balbeid; Agus Saleh Atmadipoera; Alan Frendy Koropitan
Jurnal Ilmu dan Teknologi Kelautan Tropis Vol. 7 No. 2 (2015): Elektronik Jurnal Ilmu dan Teknologi Kelautan Tropis
Publisher : Department of Marine Science and Technology, Faculty of Fisheries and Marine Science, IPB University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (988.47 KB) | DOI: 10.29244/jitkt.v7i2.11035

Abstract

Madden-Julian Oscillation (MJO) is a large-scale phenomenon that occurs in equatorial area, parti-cularly Indonesia. This research aimed to investigate the MJO propagation process and studied the correlation between MJO and sea surface temperature (SST) and chlorophyll-a. Sea variables (SST and chlorophyll-a) and atmosphere variables (outgoing longwave radiation/OLR, 1,5 km wind, and surface wind) were band-pass filtered for 20-100 days period. Spectral density from OLR and 1,5 km wind (2003-2012) shows that the MJO period was dominantly occurred for 40–50 days. Average pro-pagation of  MJO velocity resulted from the atmospheric variable analysis by Hovmöller diagram was 4,7 m/s. Cross correlation between SST and OLR in South Java and Banda Sea results a strong corre-lation during MJO active phase, where MJO took  place first and was then followed by the decreasing SST along the equatorial region. Increasing chlorophyll-a concentration occured at some areas du-ring MJO active phase with relatively short phase delay. During the MJO active phase, fluctuation of wind velocity generates variation over mixed layer depth and triggers upwelling /entrainment. Nutri-ent was upwelled to the water surface and hence increase phytoplankton production and chlorophyll-a concentration. Keywords: Madden Julian Oscillation, OLR, sea surface temperature, surface chlorophyll-a
SPATIAL AND TEMPORAL VARIATION OF INDONESIAN THROUGHFLOW IN THE MAKASSAR STRAIT Agus S. Atmadipoera; Selfrida M. Horhoruw; Mulia Purba; Dwi Y. Nugroho
Jurnal Ilmu dan Teknologi Kelautan Tropis Vol. 8 No. 1 (2016): Elektronik Jurnal Ilmu dan Teknologi Kelautan Tropis
Publisher : Department of Marine Science and Technology, Faculty of Fisheries and Marine Science, IPB University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (906.704 KB) | DOI: 10.29244/jitkt.v8i1.13221

Abstract

Using outputs of INDESO model, this study investigated vertical structure, spatial and temporal variation of the Indonesian Throughflow in Makassar Strait (M-ITF). It was shown that the main axis of persistent southward jet of M-ITF formed a unique path following the western shelf slope along the strait, which was associated with a high kinetic energy (KE) region from near-surface down to the thermocline layer. Furthermore, a drastic jump of KE appeared in the narrow and deep Libani Chan-nel (near 3°S) where the strait's width shrinks significantly, thus an elevated flow velocity was needed to maintain transport volume balance. Here, maximum southward velocity at thermocline exceeded 1.2 m/s. Spatial pattern of M-ITF can be described by the first EOF mode which accounts for 79 % of the total variances. It exhibited that contours of the flow amplitudes were similar to M-ITF path, and the largest amplitude was located near the Libani Channel. Out-of-phase relationship of the flow was found between M-ITF and eddies circulation that developed in the edges of the strait. Corresponding temporal fluctuation of the first EOF mode indicated that M-ITF variabilities varied from intra-seasonal to inter-annual scales. Annual fluctuation of M-ITF was seen from EOF mode-2 (at thermocline layer) and mode-3 at lower-thermocline. Cross-spectra analysis revealed that variability of M- ITF (e.g. on annual scale) at northern entrance was highly coherent to the fluctuations of North Equatorial Current (NEC) and Mindanao Current (MC), suggesting that variability of M-ITF was remotely influenced by the Pacific low-latitude western boundary currents. Keywords: INDESO model, Indonesian Throughflow, Makassar Strait, EOF, Cross-Spectra Analysis